Many municipal programs, designed to separate recyclable materials from mixed municipal solid waste, especially the solid waste arising from residences, currently rely upon collection schemes in which a separate truck, on a separate route, must be sent out to collect the recyclables. This type of program to acquire the recyclables incurs significant extra costs over and above the normal refuse collection.
One current scheme for eliminating multiple collections involves separation and placement of recyclables by the resident into special containers which are usually the color blue. These containers can be for example, bags similar in construction to garbage bags. Containers which are selectively coded for such recycling will be collectively referred to hereinafter as "blue bags". The blue bags are usually set out on the curb alongside the regular garbage. The collection truck crew then places the blue bags containing the recyclables in the ordinary truck together with the regular garbage.
U.S. Pat. No. 5,100,005 to Noble teaches describes a method and apparatus for separating bags of recyclable materials from bags of ordinary trash by detecting bar codes placed on the bags of recyclable materials which are placed upon a conveyer belt along with the bags of ordinary trash. Noble however, relies on visually perceptable coding and identification means (i.e. bar codes) which are adequate for his application.
If however, recyclables (for example the "blue bags") are mixed together with ordinary trash to form larger loads of mixed trash, Noble's invention would be ineffective because his bags could be disposed anywhere within the three dimensional space of the load of mixed trash and thus not be detectable using sensors only sensitive to visually perceptable signals.
When a load of mixed trash (i.e. one in which recyclables and non-recyclables are mixed together) arrives at the transfer station or disposal site, the recyclables (for example the "blue bags") must be manually removed from the non-recyclable garbage. This method of manually separating the blue bags is labor intensive and therefore expensive. It also poses significant health risks to the worker who must manually sift through the garbage to separate the recyclables.
One object of the instant invention therefore, is to provide a method for separating recyclable materials from a load of mixed trash containing both recyclable and non-recyclable materials, in a quick and safe manner.
It is another object of the instant invention to provide an apparatus for separating recyclable materials from mixed trash in a substantially automated fashion and without the use of human labor.